Study On Gas Drainage Radius Of 11-2 Coal Drilling In Pan Mine

Mine gas disaster is a long-term threat to the safety of coal production in China the biggest disaster,coal gas prevention and control work without delay,at the same time,gas is also a valuable clean energy energy is very high,how to control and utilization of coal mine gas is the focus of the study of coal mine industry in our country,drainage is one of the main methods of gas control I country.In 17102(1)Yunshun construction two sets of bedding drilling,coal gas was investigated by 11-2 bedding borehole drainage radius by gas content,17102(1)Yunshun in gas drainage 38 days of the effective drainage radius is 4.5m;in the two level of the construction of the 4 group of east wind Lane wear layer drilling,using pressure method for 11-2 Coal Gas Drilling wear layer drainage radius were investigated,the study obtained two level of east wind Lane wear layer of gas drilling drainage 30 days of the effective drainage radius of 3.5m.Using COMSOL Multiphysics numerical simulation software for bedding drilling and borehole gas drainage time and vacuum extraction analysis of numerical simulation,the results show that the radius of gas drainage and extraction time exponentially,with the increase of extraction time,drainage radius will increase,but the growth rate gradually decreases;in the same drainage time under negative pressure drainage were 8KPa,15KPa,25KPa,40KPa simulation results are compared and analyzed.The results show that the change of gas pressure,the permeability,the porosity distribution is very small,when the negative pressure drainage reached 8KPa,to improve the gas drainage pressure on coal seam gas drainage radius has little effect.The effect of control on gas mining 11-2 Coal seam are evaluated respectively from pumping,gas drainage rate,residual gas pressure,residual gas content,residual gas desorption quantity,gas drainage rate,the total gas extraction rate were calculated and analyzed,combined with field data,and coal mine gas pumping from the ratio of the Interim Provisions,determine that the pan three mine 11-2 Coal Seam Gas Drainage Management reached the requirements,good drainage effect.